Device for dredging gravel or the like



Filed March 8, 1941 2 Sheets-Sheet 1 ooow Attorney.

Nov. 5, 1%46.

K. VON HAGEN DEVICE FOR DREDGING GRAVEL OR THE LIKE 2 Sheets-$heet 2 Filed March 8, 1941 //7ke/7z0r: urt von Has-2n by M Q, Mums/w A it may,

Patented Nov. 5, 1946 DEVICE FOR DREDGING GRAVEL OR THE LIKE Kurt von Hagen, Wissel, near Kleve, Germany; vested in the Alien Property Custodian Application March 8, 1941, Serial No. 382,443 In Germany March 8, 1940 Claims.

This invention relates to devices for dredging gravel or the like from rivers or from so-called dredge holes and the like. Up to the present time there have been used for this purpose dredging buckets operated by ropes or cables. Such dredging buckets are ordinarily operated in such a manner that the material to be removed by dredging is drawn by means of a bucket in upward direction along an inclined surface, where upon said material is discharged at the end of said surface from said bucket. Thereupon the empty bucket is again brought back to the place at which the dredging is to be done. This is accomplished by means of a system of ropes or cables adapted to move said empty bucket in a downward direction along said inclined surface so that said bucket will slide along said surface on the ground until it has arrived at the place at which dredging is commenced. In this manner of operation of the bucket the useful path of motion of the bucket forms only a relatively small part of the total path of motion of the bucket with the result that the latter will be subjected to considerable wear and will require a relatively large power for its operation. Moreover, the known plants using dredging buckets of this kind, which are drawn along an inclined plane, are connected with the further disadvantage that the bucket while being moved downward along said inclined plane and over the material to be subsequently dredged will carry with it a considerable part of the latter. In case dredging is to be done under water scoured or underwashed places are likely to occur at the end of said inclined surface. These places evidently will have to be again filled up during the upward or working motion of the bucket, such filling up greatly impairing the efficiency of the dredging plant.

In order to attain a satisfactory relation between the total path of motion and the working path of motion of the bucket it had been proposed to transfer the latter at the end of its working stroke onto a guide band by means of some kind of switching device, in such a manner that said bucket will be carried back to the place at which dredging is again to be commenced along a path of motion above the material to be dredged. Such arrangements, however, are extremely complicated and not at all adaptable, and for these reasons have not found application in practice.

My invention has for its object to provide a device for dredging gravel or other material by means of which the bucket is lifted from the 2 ground at the end of the working stroke with the aid of a carrying rope and a displaceable pulley block and thereupon carried freely suspended from the carrying rope to the place at which the material is discharged from the bucket. When carrying the bucket back to the place at which dredging is again to be commenced, said bucket will arrive at the ground only shortly before commencing its working stroke.

This is accomplished by my invention in an extremely simple way solely with the aid of a carrying rope which may at any time easily be fixed and with a pulley block through which the rope pulling the bucket is conducted.

In the drawings which form part of this specification I have represented an example of a construction of my new device for dredging gravel or the like from rivers, dredge holes and the like. In the drawings Fig. 1 is a diagrammatic view of an assembled device constructed according to my invention, Fig. 2 a detail view of the bucket forming part of said device, Figs. 3 and 4.- detail views of the aforesaid pulley block, and Fig. 3A is a sectional view taken along the line 3A-3A in Fig. 3.

Referring more particularly to the drawings, the bucket l is, drawn in known manner by means of the pull rope 2 for forward motion of the bucket, and the pull rope 3 associated with the former is drawn for backward motion of the bucket, both of said ropes being carried over rollers and 5, which are fixed to a mast 6, and wound onto the drums of a winch i.

In order to impart a positive motion to the bucket, that is in order to lift the bucket at the end of its working stroke as quickly and smoothly as possible from the ground, and in order to thereupon further move the bucket in freely suspended condition, the device is equipped according to my invention with a so-called carrying rope 8 which is secured at one of its ends to the mast t and at the other of its ends to a point at the other side of the river or the like, or on the river itself, for instance at a point of support floating on. the latter. A pulley block 9 is arranged movably on said carrying rope 8, while the pull rope 2 runs over the roller ll) of said pulley block 9. The latter may be fixed on the carrying rope 8 by means of a stop l2 mounted adjustably thereon, nd by means of a resilient hook or nose 1 l engaging said stop 12.

At the under part of the pulley block 9 are provided twoholding members l4, l5 as shown in Figs. 3 and 1, said holding members being mounted swingably about bolts l3. A stop It is provided 3 v on the pull rope 2 shortly above the bucket i. The upper free ends of said holding members I4, l5 will be moved apart when said stop 16 is moved upwardly by the pull rope 2, but upon the passage of the stop, the parts will return to latched position as shown in Fig. 3 under the force of gravity. On further upward motion .of the stop .16 on the pull rope .2 the former will engage the slotted arm ll of a bell crank lever and disengage the hook or nose H from the serves for the backward motion of the bucket i.

This backward motion of the bucket may evidently also be effected by'action of the weight .of the pulley block 9 and the bucket I themselves. In order to prevent in this case the pulley block 9 from being prematurely disconnected from the bucket, a resilient lock 22 is provided at the under part of said pulley block. The lock 2.2, however. will release the stop if; on the pull rope 2 by action of the rope 3, as'soon as the pulley block has again engaged with the stop 42 on the .ropeil or when the pull rope has been braked by the winch l. Now the bucket is still drawn back- .ward a short distance on the ground as far as to the starting point for the operation of dredging.

Fig. 3A shows the details of lock 22 when the stop i5 is releasably confined above the holding members E i and Hi. When, however, a substantial pull is exerted upon the retraction rope 3, the pull'rope flwilloccupy the angular position shown in Fig. l, and the dotted line position shown in Fig. 3. Thus, it is seen that the resilient lock 22 ,permits lateral release of stop 16 from holding members 14 and I5.

Emptying of the dredging bucket proper is effected at the place 21 at which the material is disohargedfro-m the bucket by means of a stop lever '23 or the like provided at said place. stop lever will lift a closing and clamping roller 24 or the like from the drop-door 25 of the bucket I so that said door may be opened. By pulling the bucket backward the latter will again assume its horizontal position, in which position the drop-door at the bottom of the bucket will again I be closed by action of its own weight, the roller 24 now again locking said drop-door.

:The device which forms part of my invention is connected with a number of advantages as compared with known devices of this kind. In the first place an advantage consists therein that my :new device requires only a small amount of power for its operation, this being due to the fact that the working stroke of the bucket is only of such a length is required to fill the bucket with the material to be removed by dredging. Backward motion, that isthe idle stroke of the bucket, is carried on for the greatest part in freely suspended condition of the bucket above the ground so that the total path of motion of the bucket will be free of friction on the ground and in particular there will be no impediment due to mate rial accumulating in front of the bucket which is the case with known devices of the present kind. When the carriage engages stop 12 on the backward motion, it will be necessary to apply suflicient tension to the retraction rope 3 to deflect rope 2 and stop It laterally from the bold line position to the dotted line position shown in Fig. 3; In case of dredging under water the weight of the filled bucket will be diminished by the weight of the water which is displaced thereby. With the device forming part of my invention there is furthermore no need of having the bucket climb along slopes or the like. In consequence of this, the wear of the bucket as well as of the ropes will be greatly reduced. It is also of especial importance that all moving parts are outside of the material to be removed by dredging. My new device also is essentially superior to known devices of this kind, inasmuch as the bucket may be moved with far greater velocity than is possible with known devices. In addition to this, with the device forming part of my invention there will be no difiiculties in connec .tion with work that has to be done at slopes, such as'filling up scoured or underwashed places; furthermore, by my invention there will be avoided any kind of undesirable backward dredging which is the case when sliding the bucket along the ground as is done in known constructions. My new device is especially well adapted for dredging at great depth under water. The costs of construction and maintenance of the device according to my invention are relatively small as compared with the costs of known constructions.

A further advantage of my invention consists therein that the device fordredging may easily be applied in every case and will permit the greatest possible utilisation of the ground. My new construction will also dispense with the high mast which is necessar with the known constructions of cable buckets or cable dredges in which the bucket is carried back by action of its own weight. By my invention it will be possible to attain practically unlimited widths over which the rope which serves for carrying back the bucket may be retracted.

Finally, the device forming part of my invention has the further advantage that it can be operated from all directions radially with respect to the adjustable pulley block '9. For this purpose it will only be necessary to properly displace the deflecting rollers around which the rope for pulling back the bucket is carried.

I claim:

'1. In a hoisting device, the combination of a trackway, a sheave pulley, a support for said pulley mounted on said trackway, a pull cable passing upwardly and over said pulley, means on the lower end of said cable for supporting a load, means on said support for preventing reverse movement of said cable when said load has been lifted by said cable to a predetermined position relative to said support, and means cooperating with said reverse movement prevention means for releasably resisting lateral movement of said cable, said resisting means permitting lateral release of said cable from said reverse movement prevention means upon the exertion of lateral pressure by said cable upon the resisting means.

'2. In a hoistingdevice, the combination of a trackway, a carriage mounted on said trackway, a sheave pulley on said carriage, a pull cable passing upwardly and over said pulley, means on the lower end of said cable for supporting a, load, means for preventing reverse movement of said cable when said load has been lifted by said cable to a predetermined position relative to said Carriage, and a resilient lock cooperating with said reverse movement prevention means for releasably confining the cable against lateral movement, said lock being responsive to the lateral pressure exerted by the cable to effect a cable release.

3. A device for dredging gravel or the like, comprising a pull rope, a retraction rope, and a bucket connected between said ropes, a carrying rope, a pulley block mounted on said carrying rope, said pull rope extending from said bucket and passing through the pulley block to thereby suspend the bucket, means for releasably securing said puliey block to said carrying rope at a position corresponding to the location at which the bucket substantially completes its dredging stroke, means for releasing said secured pulley block when said bucket is lifted to a predetermined position due to continued pull on the pull rope to thereby permit said block and suspended bucket to be moved along said carrying rope, means for preventing reverse movement of said pull rope and suspended bucket from said predetermined position, said last-named means permitting said pull ropeto be laterally Withdrawn therefrom by exerting a pull upon said retraction rope, and means for releasably resist-- ing said lateral withdrawal of said pull rope from said reverse movement preventing means.

4. A device for dredging gravel or the like, comprising a pull rope, a retraction rope, and a bucket connected between said ropes, a carrying rope, a pulley block mounted on said carrying rope, said pull rope extending from said bucket and passing through the pulley block to thereby suspend the bucket, means for releasably securing said pulley block to said carrying rope at a position corresponding to the location at which the bucket substantially completes its dredging stroke, means for releasing said secured pulley block when said bucket is lifted to a predetermined position due to continued pull on the pull rope to thereby permit said block and suspended bucket to be moved along said carrying rope, a pair of dogs pivotally secured to said block, the free ends of said dogs projecting in the direction of movement of said pull rope when the bucket is lifted and being yieldingly urged against opposed sides of said pull rope while said bucket is in said predetermined position, whereby reverse movement of the suspended bucket is prevented, said dogs permitting said pull rope to be laterally withdrawn therefrom by exerting a pull upon said retraction rope, and means for resisting said lateral withdrawal of the pull rope.

5. A device for dredging gravel or the like, comprising a pull rope, a retraction rope, and a bucket connected between said ropes, a carrying rope, a pulley block mounted on the carrying rope, said pull rope extending from said bucket and passing through the pulley block to thereby suspend the bucket, a stop secured on the carrying rope, means carried by the pulle block for releasably engaging said stop, said stop being located at a position on the carrying rope corresponding to the location at which the bucket substantially completes its dredging stroke, means for disconnecting said stop engaging means from said stop when said bucket is lifted to a predetermined position relative to said block due to continued pull on the pull rope, whereupon said pulley block and bucket may be simultaneously moved on said carrying rope by means of said pull rope, means for preventing the reverse movement of said pull rope and suspended bucket from said predetermined position aftersaid stop has been disconnected, said last-named means permitting said pull rope to be withdrawn therefrom by said retraction rope in a direction transversely of the longitudinal axis of the pull rope, and means for yieldingly resisting said transverse movement of the pull rope.

KURT VON HAGEN. 

